1. Field of the Invention
This invention relates to a capacitor and a method of fabricating same. More particularly, it relates to a capacitor suitable for application to dynamic random access memories (DRAMs), and a method of fabricating same.
2. Description of the Related Art
Remarkable progress has been made in technologies required for accomplishing miniaturization and a multi-layered structure, in semiconductor processes for producing semiconductor devices having a higher integration density and higher operation speed. In memory devices, however, the area occupied by a capacitor, and the capacitance hereof, must be further improved.
FIG. 4(A) is a sectional view of a storage electrode of a conventional capacitor, and FIG. 4(B) is a sectional view of a conventional fin-type stacked capacitor.
In these drawings, reference numeral 22 denotes a silicon (Si) substrate; 23 is a silicon nitride (Si.sub.3 N.sub.4 film; 24 is a polycrystalline silicon (poly-Si) film; 25 is a storage electrode; 26 is a silicon nitride (Si.sub.3 N.sub.4) film; 27 is a poly-Si film; 28 is an opposed electrode; and 29 is a fin-type stacked capacitor.
Conventionally, the storage electrode 25 of the fin-type stacked capacitor is composed of a single layer of the polycrystalline silicon (poly-Si) film 24, as shown in FIG. 4(A). Such a poly-Si film 24, however, is easily deformed or broken during etching or a thermal oxidation treatment, and therefore, to make it suitable for practical application, the poly-Si film 24 must be at least 1,000 .ANG. thick.
If the thickness of the storage electrode 25 is great in a three-dimensional structure, such as the fin-type stacked capacitor 29, which is widely applied in DRAMs, etc., as shown in FIG. 4(B), the height of the multilayered fin structure becomes even greater, and thus a multilayered wiring film such as aluminum (Al) is easily broken due to the step structure of a gate electrode, etc., and consequently, it is difficult to improve the production yield and quality.